Device for making fabrics on gripper looms



Nov. 27, 1945. A. MOESSINGER 2,389,808

DEVICE FOR MAKING FABRICS ON GRIPPER LOOMS Filed March 11, 1943 22 INVENTOR.

ALBERT MOESS/NGEE.

/ BY AW ATTORNEY.

. fabric.

Patented Nov. 27, 1945 DEVICE FOR MAKING memos N GRIPPER Looms Albert Moessinger, Wintertlmr, Switzerland. as-

signor to Sulzer Frere terthur, Switzerland s, Soeit Anonyme, Win- Application March 11, 1943, Serial No. 478,753 In Switzerland March 14, 1942 11 Claims.

The invention relates to methods and mechanisms for making fabrics on gripper looms, where the weft threads project from the fabric, in other words the se'lvage warp threads are not held together by bent-back weft threads. The invention consists in that, in a loom in which the outermost warp threads are controlled as twisted binding threads for instance by a mechanism as disclosed in my copending application Ser, No. 454,399, filed August 11, 1942, the weft threads after their insertion are kept in tension outside the warp by a holding device, at least from the moment when the warp threads or binding threads change in the shed and until the twisted binding holds the weft threads already beaten in the fabric. For this purpose a. special thread gripper can be provided which holds the weft thread in tension at least until it is beaten up in the fabric.

The weft thread already beaten-in can be taken hold of by an auxiliary thread gripper provided between the first thread gripper and the edge of the fabric, before it is released by the first thread gripper. The first thread gripper can make a stroke which is greater than'the distance between the path of the shuttle and the fabric. Preferably the thread gripper is controlled in such a way that it is opened before it makes its return motion from the fabric to the picking position.

Twisted bindings for making selvages at the neighboring edges of two adjacent lengths of fabric are already known. But such twisted bindings cannot be adopted for the two outermost sides of the fabric, where the warp threads are not held by turning back the weft threads, as for instance in all fabrics made on normal looms where the weft bobbin lies in the shuttle, or as in the case in fabrics made on a gripper loom where the ends of the threads are bent round into the next shed. A careful investigation to find the reason for this lack of success has shown that the tensionless weft thread has not sufficient resistance to sustain the binding threads, which must have a certain tension.

The invention makes it possible to make twisted bindings also at the two outermost edges of the One example of an execution of the object of the invention is shown diagrammatically in the drawing.

Fig. 1 is a diagrammatic showing my invention from above.

Fig. 2 a side view of a part of the loom at the edge of the fabric, and

Fig. 3 a side view of an auxiliary thread gripper according to the invention.

In Fig. 1 of the drawing, l is the weft thread last inserted, 2 are the warp threads and 3 the two-binding threads'o'f the twisted binding. The

the thread gripper marked 5 in Fig. 1.

weft thread is inserted by a shuttle 4 between the warp threads 2. Before the weft thread I is freed from the shuttle 4, it is held firmly by the thread gripper 5 shown in broken lines. When the weft thread I is pushed by the reed |2 against the fabric 6, the thread gripper 5 makes the same motion as the reed l2 and holds the weft thread in tension until it comes into the fabric 6 and in this way it is possible to bind the taut binding threads 3 round the weft thread I.

According to the binding of the fabric, particularly in closely beaten-up goods, some of the last bound-in weft threads vibrate or move back and forth in the fabric. During such reciprocating motion the binding of the binding threads can loosen through the bending-round of the weft threads I which are no longer held by the thread gripper 5. An auxiliary thread gripper is therefore provided to hold the already bound-in weft threads 1 According to Fig. 3, this auxiliary thread gripper 1 consists of two gripping-cheeks 8 and 9. The cheek '9 is pivotally attached to the pin I0 and is pressed against the stationary gripper cheek 8 by the spring ll. The gripper is set directly between thebinding threads 3 and the thread gripper 5. The end of the weft thread I held in tension by the thread gripper 5 and beaten into the fabric by the reed I2 is movedin between the two gripping cheeks 8 and 9. The thread gripper I can naturally also be positively controlled.

Fig. 2 shows a side view of a loom illustrating The motion of the rear point of the thread gripper is shown in dash-dotted lines a-b, b-c, cd, dia. This thread gripper is shown in its two extreme positions, in full lines a, when the thread gripper is near the fabric, and in dash-dotted lines 0 when the thread gripper brings the weft thread I from the picking position.

The thread gripper 5 (Figs. 1 and 2) consists of a supporting piece 20 driven by the loom, for

instance by a mechanism as disclosed in U. S. atent No. 2,185,308; a foot 22, provided with a guide 2|. being slideable in the supporting piece 20. A ring 23 can be set on guide 2| in any desired position, and a spring 24 is coiled around member 2| between ring 23 and the inside of the supporting piece 20.. Spring 24 pushes rod 2| upward and resiliently presses its foot portion 22 against the outside of the supporting piece 20. In this way the gripping position of the thread gripper 5 is formed. The guide 2| projects above the supporting piece 20. Close over the guide 2| is a fixed stop 25 connected to the loom.

When the thread gripper 5 has reached the edge of the fabric 6' (which is shown in full lines in Fig. 1), the supporting piece 20 first makes a movement upward (from a to b). Because of this movement the guide 2| comes up against the fixed stop 25 and the gripper 22 is opened. After that, the supporting piece 20 moves forward (from b to c), where the weft thread I is taken hold of in its picking position 26. Further, the supporting piece 20 makes a motion downward (from c to d) whereby the gripper 22 is closed. After this operation the weft thread I is held tightly and the supporting piece 20 makes a motion similar to that of the reed I2, until it comes again to the edge of the fabric 6 into the position shown in full lines.

Preferably the stroke of the thread gripper 5 is chosen so great that the weft thread I is pressed against the fabric during and after its beating up. The stroke h of the gripper 22 is consequently greater than the distance h of the weft thread I between the picked position and the edge of the fabric 6'.

Hitherto it has not been possible to adopt twisted edges on free ends, since it was impossible to make a tensioned (taut) binding of the binding threads with loose weft threads.

I claim:

1. In a loom of the gripper shuttle type and producing a twisted binding of the outermost warp threads about the weft threads with the ends of the weft threads projecting beyond the twisted warp threads, a weft thread gripping means disposed reciprocatingly movable alongside the outermost warp thread and gripping the end of always the last inserted weft thread and carrying it toward and holding it against the a fabric after the beat.

2. In a loom of the gripper shuttle type and producing a twisted binding of the outermost warp threads about the weft threads with the ends of the weftthreads projecting beyond the twisted warp threads, a weft thread gripping means disposed reciprocatingly movable alongside the outermost warp thread and gripping the end of always the last inserted weft thread projecting laterally beyond the edge of the fabric and carrying it farther in the direction toward the finished fabric than the main portion of said weft thread is transported by the beat up operation.

3."In a loom as set forth in claim 2, said gripping means comprising a controlled thread gripper firmly gripping the last inserted weft thread while said gripping means move toward the fabric and releasing the weft thread before said holding means move away from the fabric toward the picking line.

4. In a loom as set forth in claim 2, a relatively stationary holding means disposed adjacent to the edge of the last made portion of the fabric between said gripping means and the outermost'warp thread and adapted to simultaneously hold a plurality of ends of last inserted weft threads.

5. In a loom of the gripper shuttle type and producing a twisted binding of the outermost warp threads about the weft threads with the ends of the weft threads projecting beyond the warp threads, a stationary platform member disposed alongside the edge of the portion of the fabric being and just having been finished and slidingly supporting the ends of the last inserted weft'threads projecting laterally beyond the edge of the fabric, a'presser member restin on top of the weft thread ends supported by said on a stationary part of the loom and connected with and pressing said presser member toward and pressing said weft thread ends to said platform member.

6. In a loom of the gripper shuttle type and producing a twisted binding of the outermost warp threads about the weft threads with the ends of the weft threads projecting beyond the warp threads, a stationary platform member disposed alongside the edge of the portion of the fabric being and just having been finished and slidingly supporting the ends of the last inserted weft threads projecting laterally beyond the edge of the fabric, and pressing means disposed on top of said weft thread ends and resiliently pressing same to said platform member.

7. In a loom of the gripper shuttle type and producing a twisted binding of, the outermost warp threads about the weft threads with the ends of the weft threads projecting beyond the warp threads, a stationary platform member disposed alongside the edge of the portion of the fabric being and just having been finished and slideably supporting the ends of the last inserted weft threads projecting laterally beyond the edge of the fabric, pressing means disposed on top of said weft thread ends and resiliently pressing same to said platform member, and weft thread holding means disposed reciprocatingly movable alongside the outermost. warp thread and outside said pressing means and holding the end of always the last inserted weft thread projecting laterally beyond the edge of the fabric and carrying it farther in the direction toward the finished fabric than the main portion of said weft. thread is transported by the beat up operation.

8. The method of holding the last inserted weft thread, in looms for weaving, against the fabric, comprising gripping the end of the last inserted weft thread immediately after said weft thread is picked and carrying it toward the fabric while said weft thread is beaten up, and holding it against the fabric after the weft thread is beaten up. g

9. The method of holding the last inserted weft thread, in looms for weaving, against the fabric, comprising gripping the end of the last inserted weft thread immediately after said weft thread is picked and carrying it toward the fabric while said weft thread is beaten up and transporting said weft thread end in the direction toward the finished fabric farther than the main portion of said weft thread is transported by the beat-up operation.

10. The method of holding, in looms for weaving, the ends .of the last inserted weft threads projecting laterally beyond the fabric. comprising resiliently simultaneously pressing a plurality of said ends against a stationary part of the loom, and eomprisinggripping the end of the last inserted weft thread immediately after said weft thread is picked and carrying it toward the fabric while said weft thread is beaten up, and holding it against the fabric after the weft thread is beaten up.

11. In a loom for weaving as set forth in claim 1, stationary weft thread gripping means disposed between said reciprocatingly movable weft thread gripping means and the fabric and holding a plurality of said weft thread ends.

. ALBERT MOESSINGER. 

